(1) Field of the Invention
This invention relates to fluid flow, and more particularly to a check valve which permits flow in a first direction with one side up and in the reverse direction with the other side up.
(2) Description of the Prior Art
Check valves having angled valve seats and flapper valves are well known to the art.
In oil field connections, it is customary to have a check valve from a well to a pipeline to prevent flow of fluid from the pipeline back into the well. However, at certain times, it is desirable to have the connection to the valve opened. In such a situation, it is desirable not to have the fluid flowing from the well.
Before this application was filed, the applicant had a search made in the United States Patent and Trademark Office. In that search, the following patents were found:
______________________________________ GREAT BRITAIN 466,335 WHEATLEY 3,720,225 SUTHERLAND 4,090,527 EMINGER 4,141,381 KESSEL 4,259,983 BOKROS 4,272,854 ______________________________________
Applicant does not believe any of these references are pertinent, however Applicant believes the Examiner would be interested in any patent reported by an experienced patent searcher.